In accordance with one embodiment, an electrochemical cell includes an anode including a form of lithium, a cathode including an active material which intercalates lithium, and a separator positioned between the anode and the cathode, the separator including a first structured surface portion positioned in opposition to the anode, the first structured surface portion having a non-planar profile in aggregate.
In one or more embodiments, the separator has a first nominal width, the first structured surface portion defines a second nominal width, and the second nominal width is less than about 20 percent of the first nominal width.
In one or more embodiments the first nominal width is about 25 microns, and the second nominal width is about 5 microns.
In one or more embodiments, a separator includes a second structured surface portion positioned in opposition to the cathode, the second structured surface portion having a non-planar profile in aggregate.
In one or more embodiments a separator has a first nominal width, the first structured surface portion defines a second nominal width, the second structured surface portion defines a third nominal width, and a sum of the second nominal width and the third nominal width is less than about 20 percent of the first nominal width.
In one or more embodiments the first structured surface portion is uniformly structured, and the second structured surface portion is uniformly structured.
In one or more embodiments the first structured surface portion includes a plurality of first surfaces angled with respect to each other, and the second structured surface portion includes a plurality of second surfaces angled with respect to each other.
In one or more embodiments each of the plurality of first surfaces is separated from another of the plurality of first surfaces by a rounded corner portion, and each of the plurality of second surfaces is separated from another of the plurality of second surfaces by a rounded corner portion.
In one or more embodiments each of the plurality of first surfaces is associated with a respective one of the plurality of second surfaces located directly across the width of the separator, and a straight line distance from each of the plurality of first surfaces to the associated one of the plurality of second surfaces is the same distance as a parallel straight line distance between each of the other of the plurality of first surfaces to the associated one of the plurality of second surfaces.
In one or more embodiments each of the first structured surface portion and the second structured surface portion are irregularly textured.
In one embodiment, a method of forming an electrochemical cell includes providing an anode including a form of lithium, providing a cathode including an active material which intercalates lithium, forming a separator portion, forming a first structured surface portion of the separator portion, the first structured surface portion having a non-planar profile in aggregate, and positioning the formed separator portion with the first structured surface portion between the anode and the cathode with the first structured surface portion in opposition to the anode.
In one or more embodiments forming the separator portion comprises forming the separator portion with a first nominal width, and forming the first structured surface portion comprises forming the first structured surface portion with a second nominal width, wherein the second nominal width is less than about 20 percent of the first nominal width.
In one or more embodiments a method of forming an electrochemical cell includes forming a second structured surface portion, the first structured surface portion having a non-planar profile in aggregate, wherein positioning the formed separator portion between the anode and the cathode comprises positioning the second structured surface portion in opposition to the cathode.
In one or more embodiments forming the first structured surface portion comprises uniformly structuring the first structured surface portion, and forming the second structured surface portion comprises uniformly structuring the second structured surface portion.
In one or more embodiments forming the first structured surface portion comprises forming a plurality of first surfaces angled with respect to each other, and forming the second structured surface portion comprises forming a plurality of second surfaces angled with respect to each other.
In one or more embodiments forming the first structured surface portion comprises separating each of the plurality of first surfaces from another of the plurality of first surfaces with a rounded corner portion, and forming the second structured surface portion comprises separating each of the plurality of second surfaces from another of the plurality of second surfaces with a rounded corner portion.
In one or more embodiments forming the second structured surface portion includes forming each of the plurality of second surfaces directly across the width of the formed separator portion from an associated one of the plurality of first surfaces, such that a straight line distance from each of the plurality of first surfaces to the associated one of the plurality of second surfaces is the same distance as a parallel straight line distance between each of the other of the plurality of first surfaces to the associated one of the plurality of second surfaces.
In one or more embodiments forming the first structured surface portion comprises scraping a first outer surface of the formed separator portion to form an irregular texture on the first outer surface, and forming the second structured surface portion comprises scraping a second outer surface of the formed separator portion to form an irregular texture on the second outer surface.
In one or more embodiments forming separator portion includes forming the separator portion on a scaffold having a desired surface structure, and releasing the formed separator portion from the scaffolding, such that forming the separator portion comprises forming the first structured surface portion.
In one or more embodiments forming the first structured surface portion includes chemically etching the formed separator portion.